Block-signal system.



PATENTED FEB. 19, 19-07.

L. A. HAWKINS. BLOCK SIGNAL SYSTEM.

APPLICATION FILED JULYsl, 1905- 2 SHEETB BHEBT I Inventor.

Witnesses.

Laurence fLHawhins.

by z

flttg.

No. 844,797. PATENTED FEB. 19, 1907.

L. A. HAWKINS- BLOCK SIGNAL SYSTEM.

APPLICATION FILED JULY31, 1905.

2 SHEETS-SHEET 2.

Witnesses. Inventor. M23414, Laurence fl. Hawkins by MW UNITED STATES PATENT OFFICE.

LAURENCE A. HAWI {I-NS, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BLOCK-SIGNAL SYSTEM.

Patented. Feb. 19, 1907.

Application filed Jul 31,1905. Serial a. 271,871.

To all whom it mag concern:

Be it known that I, LAURENCE A. HAW- runs, a citizen of the United States, residing at Schenectady, in the countyof Schenectady and State of New York, have invented certain new and useful Improvements in Block-Signal Systems, of which the following is a specification.

My'invention relates to block-signal systems, and particularly to systems adapted to give an indication at the. entrance of each block of the condition both of that block and the following block or, in other words, to give clear, caution, and danger indications. Signals for giving these three indications have been arranged heretofore either with two arms, each adapted to assume two different positions, or with a single arm adapted to assume any one of three positions. My invention is equally applicable to both types of signals and will be illustrated and described in connection with both modificaqtionsx Two general types of systems for controlling such signals have been commonly used heretofore. In one type of system wires are extended back from each block to the signal at the entrance of the preceding block, so that each signal is controlled not \only by trains in its own block, but also by trains in the following block. The second system, which has been used heretofore, emplogs' no Wires connecting ad acent signals, an

the rails themselves furnishthe only eletricalconnection. The control of one signal the bloc In a ormer application, Serial No. 217,212

filed by me July 19, 1904, I'have shown an arrangement in which a single armature accomplished the same results which have been accomplished before by means of two armatures, one neutral andjone polarized. As fully ex lained in my former application, I

iaccomp ish this result by arranging the relay so that the armature has three different pos1-.

isions-an ofi position and an operative position-on each side of the off position. Such a relayirascertain disadvantages, since the 0H a position is less definite than 1n the case of an armature having only two positions.

The objlect of my present invention is to accomplisi the same results with a single armature having only two positions.- 1 accomplish this by controlling the track-relay not only by trains in that block and in the following block, but also by the signal which is itself controlled by therelay.

More specifically stated, my invention consists in the combination, with a signal adapted to give clear, caution, and danger indications, of a source of current connected to the i'ail-circuit at the exit end of the block,

a reversing-switch in circuit with the source and controlled by a train on the following. block, a relay connected to the rail-circuit at the entrance end of the block and controlling the signal, and means controlled by the signal for reversing the connections of the relay to the rail-circuit. As will appear later in this specification, a relay having a perma:

nently-polarized armature would operate satisfactorily in the above system, as far as trains passing in one direction over a main line are concerned, but Wouldnot operate properly when a train ran off a block onto a siding. In order to secure proper operation under all conditions whatsoever, I so arrange the relay that it has a neutral armature 1n certain positions of the signal and a polarized armature in other positions.

Accordingly, one feature of my invention consists in the combination, with a signal, of a track-relay controlling the signal and having means controlled by the signal for rendering the armature of the relay polarized in one or more positions of the signal and non-polarized in another position.

My invention will be best understood by reference to the accompanying drawings, in

Figure'l shows a block-signal system arranged in accordance With my invention, thesignals shown being of the one-arm three position type. Fig. 2 shows a similar arrangement applied to the control of two-arm two-position si nals,'and Fig. 3 shows a .view of the traclr-relay.

Referring first to Fig. 1, T, T, and T represent three railway-blocks electrically insulated-from each other.

The block '1 is.

ICC

ger, this ,eing accomplished bya single arm -assuming three different positions as shown.

shown occupied by a car or train t. S, S, and S? represent signals at the entrance to the respective blocks. vThese signals are adapted to give three distinctindications, correspondin 'to clear, caution, and dan- ;the motor to the signal and release it therefrom, and a lock-magnet L, adapted to lock the signal at caution and clear positions. B represents a source of current for the operating mechanism of the signal S. R represents the track-relay connected to the entrance end of the block T and provided with a neutral armature r. m represents a magnetizing-coil adapted Whenenergized'to polarize the armature r. A represents an auxiliary relay'controlled by the track-relay R and by the signal S, as will be hereinafter explained, and having four armatures, as

shown, byymeans of which it control-s the signal S in certain positions thereof conjointly with the track-relay R and also serves to reverse the connections of the relay R to the railcircuit. The rails of the block T at the exit end of the block are connected, through the reversing-switch 0 controlled by the signal S, to the track-battery 6 The signals S, S, and S are operatively connected to the controlling-switches s, 8 45 and .9 which may be of any suitable type, but which, for the sake of clearness, are shown with movable contacts developed on a plane surface adapted to be engaged by 1 I stationary contact-fingers, as shown. The 5o motor-circuits are shown in heavy lines, while the circuits of the relays and the lockmagnets are shown in light lines.

The operation of the system is as follows; With a trainon a block, as shown at block T the track relay R is short-circuited, and V consequently drops its armature to the position shown, thereby breaking the circuit of motor, clutch-magnet,\and lock-magnet and' allowing the signal S to be carried to danger position by its counterweight, as shown. It

" will be noticed that the circuit ofJthe magnetizing-coil m is open at the left-hand contact;finger of switch 8 so that the armature is not polarized. This condition of aflairs continues as long as the train is in the block The specific construction and ararmature rithrough the armature a of aux-- iliary relay A to'the back contact of this armature", through the switch 8 clutch-m agnet C motor M to the upper tern inal of battery B sequently closed, and the motor starts, driv ing thesignal S from danger to caution osi- The circuit'of motor and clutch is contion. When caution position is reache the conditions of the circuits will ,be tlte same as shown in the drawings for the signal S By referring to the circuits of the signal S it will be seen that the circuit of the motor and the circuit of the, lock-magnet L has been closed. I Furthermore, the circuit of the mag-. netizing-coil m is closed, so that the ar;na--

ture 1' is polarized. The polarization is in such a d rection, however, as long as the signal S is at danger that the attraction of' the relay R on its armature is not affected or merely somewhat increased. It will be seen that the track-batteries b and b are connectpreceding block are reversed. The circuit connections of the signal S remain as shown as long as a train is in block T and the signal 8 remains at danger. When the train passes out of this block and the signal S is driven from "danger to caution in the manner that has been above explained, the connections of the track-battery b are reversed, thereby sending current through the relay R in the opposite direction. armature r is now polarized, this reversal of current in the relay R causes the relay to dropits armature momentarily. When the armature is dropped, a circuit is closed from clutch has been broken by the switch 8 while Since the the lower terminal of the battery B, through the relay-armature a, through the back contact of the armature, through the auxiliary relay A through the switch 8 to the up er The auxiliary re ay term inal of battery B A is consequently energized and draws up its 'four armatures. The two lower armatures for in a reversing-switch for the track-relay R so that the direction of current through this relay winding is again reversed, and it draws up its polarized armature r practically instantaneously. The relay-arznature a is arranged to short-circuit the back contact of the relay armaturer so as to close a maintaming-circuit for the winding of the relay A Oonsequentlythis auxiliary-relay is not denergized when up its armature;

1%? track-relay again picks e upper armature a of 43c 'net L.

and drive the signal from "caution to' clear. The condition ofthe circuits at clear position is shown for signal S. Both the track-relay R and auxiliary relay A maintain their armatures raised Whilethe switch 8 has broken the circuit of motor and clutch and has closed the circuit of lock-magmains clear until a train again comes onto the block. The track-relay R is thenshOrtcircuited, opening the circuit of the lockmagnet and allowing the signal to be carried to danger position by its counterweight. It is to be further noted that the signals behind a. train will -be operated correctly when a train backs onto a block. For instance, if a train on block T should back from block T 3 to block T it would short-circuit the track:

relay R and allow the signal to go to dana, *2 ger. This move dent of the signal b would reverse the connections of the track-battery b, thereby reversing the dlrection of currentfiow through the relay-WindmgR. The relay R would consequently drop its armature and the counterweight would start the signal S toward danger position. The signal would not pass beyond or at least much beyond caution position, for as soon as the circuit of the auxiliary. relay A is broken by the switch 8 at or a little beyond caution position the relay A would drop its armature, thereby again reversing the current-flow to the trackrelay. The track-relay would consequently pick up its armature, closing the lock-circuit to hold the signal at caution position, or if the signal has passed somewhat beyond caution position it would close the circuit of the clutch and motor to run the signal back'to caution position. W'hen caution position-is reached, the motor and clutch would be cut out and the lock-magnet cut in in the manner heretofore explained.

As far as the explanation given heretofore is concerned the operation wo: ld be precisely the same as described if the track-relays had permanently-polarizedarniatiires. Such an arrangement, however, WOlIlCl not perate the signal ahead of the train satistactorily when a train leaves a block by backing off it or the signals behind a train when it leaves a block by running onto a siding. The reason for this is that the signal for the following block wouldthlen be at clear position,-so that if a polarized relay were properly connected to respond when the following I track-relay. The relay-coilis indicated at signal is at danger position it would not rea train backed off a block.

When a signal is thus cleared, it re-' spond at all with the following signal at clear position when the train left the block by running onto a siding-that is, the signalwould remain at danger position. The same thing as regards the signal ahead would happen if It is in order to take care of such conditions of operation that the relay is so arranged that part of the time it is neutral and part of the time polarized.- With such a relay the system will operate satisfactorily, not only for trains proceeding in either direction over the main line, but also for trains leaving a block by running onto a siding. This is clear from the following con siderations: When the train leaves the block, removing the short circuit fromthe relay, the relay will pick up its armature, regardless of the position of the following signal, since the tion position is reached or nearly reached,

when the circuit of themagnetizing-coil is closed, as has been heretofore explained. If

the-following signal is at caution or clear position, as would be the case when a train runs off the block onto :1 Siding, instead of at danger position, as would be the case when a train runs off a block onto the following block, the directionof current through the track-relay would be such that when the armature is polarized itdrop's the armature momentarily; but this momentary dropping of the armature closes the circuit of the auxiliarv relay, reverses the connection of the track-relay to the rails, and causes it to pick' up its armature again instantaneously. The motor and clutch-circuit would consequently be maintained closed and themotor would drive the signal from caution to clear position. It should be noted that the contacts on the signal operated switches s 8 850., should be so arranged that the movable contact connected to the front contact of the upper armature-of the auxiliary relay will have engaged its corresponding contact-fin ger by the time the auxiliaryrelay picks up. In Fig. 2 I have shown the same system as heretofore described applied to the control of signals adapted to give clear, caution, and danger indications by means of two, two-position arms, which are known as home and distant signals, and which in the drawings are indicated by the letters H and D.

In this figvre, for the sake'of simplicity, the

clutch and lock magnets of Fig. 1 are omitted," and the operating mechanism for the signals H and D are merely indicated by the motors M, and M,, respectivel This renders it possible greatly to simplify the representation of the controlling-switch sl The operation of the system is exactly the same as has been heretoforeexplained and requires, no further discussion.

Fig. 3 shows a suitable arrangement for the ITO its-outerend a contact f, adapted to engage a stationary contact F when the armature 1' is attracted by the relay-magnet. The relayarmature 1" .is surrounded by a suitable stationary magnetizing-coil m, which when energized polarizes the relay-armature.

It will be understood that I have represented my invention diagrammatically and that in practice any suitable form of apparatus may 7 be employed. Furthermore, many variations in the circuit connections may be made without in any way altering the mode of operation. -For instance, it is utterly immaterial whether the reversingswitch controlled by the a" xiliary relay is in circr it with the main magnet-winding of'the relay, or of the magnetizing-winding. Accordingl I .do not desire to limit myself to the partic' lar COIlStFlCtiOIl and arrangement of partshere shown, but aim in the appended claims to cover all modifications which are within the scope of my invention.

What I claim as new, and desire to secure by Letters Patent oi the United States, is-

1. Ina block-signal system, a signal adapted to give clear, caution and danger indications, a track-relay controlling said signal,

'nal controlled bysaid relay, means controlledmeans controlling said relay and controlled by a train in the following block, and means controlling said relay and controlled bysaid signal.

2. In a block-signal system,a signal at the entrance of a block adapted to give clear, caution and danger indications, a source of current connected to the rail-circuit of the block, means controlled by a train. in the following block for reversing the connection of said source to the rail-circuit, a relay connected to the rail-circuit of theblock and controlling the signal, and means controlled by the signal for reversing the connectionsof a winding of said relay,

3. In a block-signal block, a relay, and two reversing'ewitches, one of said switches being inserted in circuit between said source and the rails and the other between t" e rails and said relay a sigby a train in the following block for operating the first reversing-switch, and means controlled by said signal for operating the second I reversing-switch.

, 4. In a block-signal system, asignalat the entrance of a block adapted'to give clear, caution and danger indications, a track-relay controlling said signal, a source of current connected to the rail-circuit of the' block,

. means for reversing the connections of said source when a train leaves the following block, and means for reversing the connecsystem, a circuit com prising a source of current, the rails of the tions of a winding of the relay when the relay is denergized and the signal is at caution.

5. In a block-signal system, a signal at the block, a track-relay controlling said signal,

an auxiliary relay, contacts controlled by. said track-rela andb sa1d signal in circuit with said auxi iary re ay, and a reversingswitch in circuit'with a wlnding of the trackrelay controlled by the auxiliary relay.

6. In a block-signal system, a signal at the entrance of a block adapted to give clear, caution and danger indications, a source of current connected to the rail-circuit of the block, a reversing-switch in circuit with'said source'controlled by a train in the following block, a track-relay controlling said signal,

an auxiliary relay, a circuit for said auxiliary relay comprising a back contact of tlle trackrelay and contacts controlled by the signal and closed when the signal is at caution, and a reversing-switch in circuit with a winding of the track-relay and controlled by said auxiliary relay.

' 7. In a block-si'gnal system, a signal at the entrance of a block adapted to give clear, caution and danger'indications, a source of current connected to the'rail-circuit of the block, a reversing-switch in circuit with said source controlled by a train in the following block, a track-relay controlling said signal, an auxiliary relay, a-circuit for said auxiliary relay comprising a back contact of tie track'- relay and contacts controlled by. the signal and closed when the signalis at caution, a

reversing-switciiin circuit with a winding of the track-relay and controlled by said auxiliary relay, and a contact controlled by said auxiliary relay'adapted to short-circuit said backcontact of the track-relay,

8. In a block-signal system, a signal at the entrance of a block adapted to give clear,

caution and danger indications, a source of current connected to'the rail-circuit-at the exit end of the block, a switch in the connec:v

tions between said source and rail-circuit controlled by a trainin the following block, a track-relay: connected to the rail-circuit at the entrance off'the block controlling said:

tam positions .0 said signal,and a-circuit for signal, anauxiliary' rela controllin said signal-conjointl'iy with sai track-relay in cer- 1 2o said arniiliary relay including a back contact of the track-relay and contacts controlled by the signal. v '9. In a block-signals stemga signal at the entrance of a block adapted to give clear, caution and danger indications, a source of current connected to the rail-circuit at the exit end of the block, a switch in the connections between said source and rail circuit controlled by a t ain in the following block, a track-relay connected to therail-circuit at the entrance Of'JllG block controlling said sig-' nal, an auxiliaryrelaycontrolling said signal, conjointly with said track-relay in certain positions of said signal, a circuit for said auxiliary relay'including a back contact of the track-relay and contacts controlled by the signal, and a contact controlled by said auxiliary relay a apted to short-circuit said back contact of the track-relay,

10. In a block-signal system, a signal at the entrance of a block adapted .to give clear, caution and danger indications, a source of current connected to the rail-circuit of the block, a reversing-switch in circuit with said source andcontrolled by a train in the following block, a track-relay having a neutral armature connected to the rail-circuit of the block and controlling said signal, and means.

for polarizing said armature when the signal is at caution or clear.

11. In a block-signal system, a signal at "the entrance of a block adapted to give clear,

caution and danger indications, a source of current connected to the ra1l-c1rcu1t of the I block, a reversing-switch incircuihwith said source and controlled by a train'in'the following block,-'a track-relayhaving. 'a neutral armature-connected to the rail-circuit of the block and controlling said signal, a winding adapted when energized to polarize said armature, and contacts in circuit with said winding controlled by the signal.

12. In a block-signal system a signal at the entrance of a block adapted to give clear, caution and danger indications, a source of current connected to the rail-circuit at the exit end of the block, a reversing-switch in circuit with saidsource and controlled by a train in the following-block, a track-relay 'havinga neutral armature connected to the iail circuit at the entrance of the block and controlling saidsignal, a winding adapted when energized to golarize said armature,

by the signal for enerwhen the signal is at and means controlle caution or clear.

13. In a block-signal system, a circuit comprising a source of current, the ra1ls of a 'ized in another block, a relay, and two reversin, ;-switches, one of said switches being inserted in circuit between said source and the rails and the other between the rails and said relay, means ture of said relay polarized in one or more positions of said signal and non-polarized in another position.

14. In a block-signal system, a signal at the entrance of a block adapted to give clear, caution and danger indications, a track-relay controlling said signal, a source of current connected to the rail-circuit at the exit end of the block, means for reversing the connections of said source when a train leaves the following block, means for reversing the connections of a winding of the relay when the relay is deenergized and the signal is at caution, and means controlled by the signal for rendering the armature of the track-relay polarized when the signal is at caution or clear and non-polarized when the signal is at danger.

15. In ,a block-signal system, a signal, a

track-relay controlling said signal, and. means controlled by the signal for rendering the armature of said relay polarized in one or more positions of said signal and nonpolarosition. 16. In a bloc -signal system, a signal, a track-relay controlling said signal, said relay having a neutral armature,a winding adapted when energized to polarize said armature, and contacts in circuit with said winding controlled by said signal, said contacts being arranged to close the circuit of said winding to polarize the relay in certain positions of said signal and to open the circuit of said winding in other 'positions of said signal.

In witness whereof I have hereunto set my hand this 29th day of July, 1905.

. LAURENCE A. HAWKINS. 

